Four stroke cycle engine



Noir. `10, 1931.- M. BLAU E1' AL soun-STROKE CYCLE Emma Filed April 5, 1927 5 Sheets-Shgt 1 an f agmvew/arf M. BLAU ETAL FOUR-STROKE CYCLE ENGINE Nov. 1o, 1931.

5 Sheets-sfusi 2 Filed April 5, 1927 Nov. 10, 1931. M. BLAU ET AL FOUR-STROKE CYCLE ENGINE Filed April 5, 1927 5 Sheets-Sheet 3 Nov. l0, 31931. ELM.; Aa.. 1,831,155

` FOUR-STROKE CYCLE ENGXNE Filed April 5, 1927 5 Sheets-Sheet 4 Nov. l0, 1931.

NIf BLAU ET AL FOUR-STROKE CYCLE ENGINE Filed 11pm 5, 1927 5 sheets-sheet 5 Q ,NAW

Fatener Nov. it),

yUNITED STATES PA'IENT;v OFFICE MARTIN BLAU, OF ERFENSCHLAG, NEAR CHEMNITZ, AND 'EMIL FREYTAG, OF ZWICKAU,

GERMANY i FOUR STROKE CYCLE ENGINE Applicationy filed April 5, 1927, Serial No. 181,189, and in Germany April 9,1926.

Our invention relates to internal combustion engines and more particularly to an improved engine of the four stroke cycle type.

The construction of cert-ain internal com- 8 hustion engines especially of the four stroke cycle type, is objectionable for the reason that the channels or ports for the admission of the fuel and air mixture are of a considerable length and provided, in most cases, with valves, whereby the movement of the fuel and air mixture towards and to the cylinder or cylinders will be retarded, so that incomplete admission or filling of the cylinders ensues. This defect is the more objectionable in engines particularly designed and intended for high degrees of admission and in which, therefore, the crank case is utilized for a preliminary compression, that is the production of a previously compressed mixture.

The object of our invention is to remedy this defect and with this object in view we provide comparatively short ways or channels for the admission of the fuel and air mixture, and we dispose such channels in a manner which is particularly suitable for ensuring practical advantages such as economy and reliability or commercial and relative efficiency, in engines of quite a variety of constrnctional modifications.

Other detailed features of the invention will be hereinafter specifically described and then pointed out in the claim.

The inventive idea involved, therefore, is capable of expression in a variety of mechanical forms, three of which for the purpose of illustration are shown in the accompanying drawings, but it is to be understood that said drawings are for the purpose of illustration only, and not for the purpose of defining the limits of the invention, reference being had to the claim for this purpose.

In said drawings Figure 1 is a sectional view of the cylinder casing of an engine constructed according to the present invention; Figure 2 represents a similar section of the same taken on a plane perpendicular to that of Figure l; Figure 3 is a sectional view of the cylinder casing of a modified construction (four-stroke c vcle engine); Figure 3a represent-s the same type with slight modifications as is suitable for operation according in section a portion of the one cylinder shown in Figure 5 on an enlarged scale and with the 60 piston in a different position; Figure 7 is a View similar to Figure 6, but with the piston in a, third position; and Figure 8 is a sectional view of the engine shown in Figures 5 to 7, but modified to form a compressor.

Referring to the embodiment of the invention shown in Figures l and 2 the engine substantially comprises a cylinder l, a oompression chamber 2 integral and communr eating with the cylinder l, an admission valve 3 located in the wall of the said chamber, an exhaust valve 4, a piston 5 and a crank case 6. v

As hereinbefore mentioned, the purpose aimed at by the present invention is to ensure a particularly high compression and efficiency and for this reason the crank ease. is utilized as an auxiliary means for charging the cylinder. An essential feature of the invention resides in the short admission conduit or channel 9 immediately connected, for oommunication, with a Carburettor (not shown) and having two branches 7 and 8 the length of which, taken both together, is approximatelyequal to the length of the stroke of 35 the piston. It will be'seen that no valves or any other shutting-off gears are provided in the channel for the admission of the fuel and air mixture or in the two branches there of, so that just owing to, the fact that any such obstacles are dispensed with. the charge will have a thoroughly free passage to flow without restraint into both thev compression chamber and the crank case.

The operation of the engine is as follows: Supposing the piston has just accomplished the compression strok'e so as to occupy the position shown in Figures 1 and 2. Now, due to the movement of the piston towards the compression chamber a vacuum has formed 10 in the crank case and fuel and air mixture is drawn into the crank case 6 by suction through the branch 8 of the channel 9. In or during the subsequent working stroke of the -piston the charge inv the crank caseis compressed and caused to flow, when the working stroke is finished, through an overfiow channel 10,:4 into the working space of the cylinder, after the exhaust valve 4 had previously opened. The fresh charge thus admitted into the cylinder acts to expel the exhaust gases or products of combustion from the cylinder and to fill the compression chamber 2 after the subsequent return or inward movement of the piston. On the next outward movement of the piston, that is the suction stroke. fuel and air mixture is drawn in through the branch 7 of the channel 9 and the admission valve 3, so that, at the moment the piston has finished its suction stroke. a a quantity of charge is contained in the cylinder, which comprises two different mixtures of charge viz the crank charge and the charge coming from the carburetor. l time, however, as the piston carried out its outward or suction stroke, as described, again the fuel and air mixture contained in the crahk'case has been compressed and caused to flow over, at the moment a slot 11 provided in the piston wall has movedl down so far as to register with the orifice 10*1 of the channel 10, into the cylinder and mix with the chargev already contained therein', so that the total charge comprises three'single charges, namely, a charge from .the crank case, a charge from the carburetor and a third charge entering from the crank case under presure.

Internal combustion lengines as hitherto constructed are not capable yof forcing highly voluminous charges, as above described, into L their cylinders since the movement of the fuel and air mixture is too much retarded in and by the long way through the admission passages and by the valves usually provided therein. It will be seen therefrom that the resent invention is a I remarkable advance 1n the art. v

In the embodiment shown in Figures 3 and 4 the construction and arrangement of the admission channel 9 including the branches 7 and 8, andthe mode of charging are the same as described with reference to Figures 1 and 2 with the sole exception or difference that the exhaust valve .is dispensed with and an auxiliary piston 12 is substituted therefor for the purpose of controlling an exhaust port 13. The auxiliary piston 12 produces work in the same manner as the real working or mam p1ston 5. The work, energy or movement of the two pistons Vis transmitted'to a shaft 17 by means of a spur gear system com-A prising the three wheelsll; 15 and 16, but the two pistons do not work in the same cycle, for the auxiliary piston 12 accomplishes two strokes only during the time or period in At the same which the main or working piston 5 performs four strokes.

The co-operation of the two pistons 5 and 12 is diagrammatically shown in Figure 4, the arcs or segments A, A denoting the working strokes,'l3, B the exhaust strokes, C, C the suction strokes and D, D" the compression strokes of the two pistons, respectively. Obviously the stroke C of the auxiliary piston 12 is not a real suction stroke, since the same counteracts the suction stroke of the Working piston 5. This fact, however, is practically immaterial on account of the particular charging mode and the great, voluminous charge obtained thereby.

As the auxiliary piston is in advance of the main or working piston during the working stroke and consequently has gone considerably far beyond the inner dead centre at the time the explosion occurs, the working piston will be safely prevented from striking back, for instance, on starting the engine.

If the wheels 14, 15 and 16 are replaced by wheels such as 18, 19 and 20, respectively, as shown in Figure 3, and if the bearings of the shaft 17 are displaced to an amount as indicated by c', the two pistons will be adapted to work on the same cycle and the engine will run on the two stroke cycle method. Obviously a suitable sealing member must be substituted in such a case for the suction valve 21. A two stroke cycle motor is particularly useful in cases where the load is invariable whereas in case of load variation a four stroke cycle engine will be preferable. As regards manufacture the described two motor types are particularly advantageous inasmuch as they consist of and comprise the like individual parts or members.

In the modification illustrated in Figures 5 to 8 the engine comprises two cylinders a and b with pistons c and d, respectively. The. pistons c and d are interconnected to move simultaneously in opposite phase of the cycle, that is to say, when the explosion occurs or the working stroke takes place in the cylinder a, fuel and air mixture will be drawn or sucked into the cylinder b or, in other words, the cylinder b will be charged at the same time, and vice versa, each time the working stroke is accomplished in the cylinder b,

the cylinder a will be charged.

those indicated by the arrows e and f in Figure 7, the admission conduits are closed and the mixture in the crank case is compressed while at the same time a vacuum is produced in the chamber la in front of the piston a?. As the piston d continues to move inwards, a cupshaped recess Z provided in the outer peripheral wall of the piston, will coincide or register with the channel L and practically at the same time with the outlet of a passage m, forming a communication between the cylinder and the admission valve n. The outlet of the passage m is located in close proximity to the outlet of the channel h and it will be seen, upon inspection of Figures 5 and 6, that when the cup l reaches the point to register with the two outlets, the fuel and air mixture will low from the Carburettor g through the channel 7L, the cup Z, the passage m and the admission valve n into the evacuated chamber 7c in front of the piston d.

As the piston d further continues to move in the direction towards the crank case the just described communication between the Carburettor g and the chamber 7c will be cut ofi' and communication between the chamber c and the crank case i will be established through or by means of a slot o provided in the piston wall close by and in front of the cup l and adapted to coincide or register With the outlet of the channel h immediately after the cup Z has passed over the same. As

the mixture in the crank case is highly compressed due to the movement of the two pistons towards the crank case, it will iiow through the slot o, the passage m and the admission valve n into the chamber lo which, at that time, already contains a full charge of fuel and gas of atmospheric or normal pressure. Figure 7 illustrates the position of the parts or the moment at which gaseous mix'- ture is going to be expelled from` the crank case through the slot o into the passage m. It will be seen that in this manner the charge of the cylinder will be increased to about more.

As the cups Z in the two pistons c and al are absolutely level with the outlets of the passages n and m, the carburetor will simultaneously communicate through the cup with the valves 'n of the two cylinders but the mixture formed by the carburetor flows only into the combustion chamber of that cylinder which is just making the suction stroke. Al-

spring) keeps the suction valve closed. This operation takes place alternately in each cylinder.

It is apparent that the charging o eration described with reference to the cylinder b likewise takes place in the same manner in the cylinder a of Fi ure 7, when the'piston 0 performs its charging stroke while simultaneously therewith the piston d accomplishes its working stroke.

Obviously an engine constructed as herinbefore described can be converted into a iston compressor without requiring consi e able reconstruction, it being necessary only to remove or dispense with the Carburettor and the rodwork controlling the exhaust valves. In Figure 8 we have shown a portion of a compressorl equipped with an outlet or delivery valve p devoid of any actuating members and adapted to open towards the outer air and to be opened bv the action of the compressed fluid during t e compression stroke of the piston. During the suction stroke of the piston the delivery valve is held on its seat either by a suitable spring or by the overpressur in the delivery conduit. As regards the valvemechanism, therfore, the suction and delivery valves as usually employed in piston compressors, do not necessitate any change. In case of a multi-cylinder compressor a separate crank case may be provided in connection with each single cylinder or any plurality of pistons working in the same direction may be provided with a joint crank case.

From the foregoing specifications it will be seen that simple and efficient means are herein provided for accomplishing the objects of the invention, but while the elements shown and described are well adapted'to serve the purposes for which they are intended, it is to be understood that the invention is not limited to the precise construction set forth, but includes within is purview such changes as may be made within the scope of the appended claim. three times the volume of the piston or still l What we claim is Internal combustion engine of the four stroke cycle type comprising in combination a working cylinder with inlet for a fuel mixture and outlet for the waste gases, a working piston in the cylinder, a controlling piston for controlling the outlet in a further cylinder, the latter being arranged at an acute v angle to the first named cylinder and having one common combustion chamber with the first named cylinder, each piston acting on an interchangeable driving wheel, an interchangeable central wheel engaging with both driving wheels and driven by the latter, a

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crank case also serving for preliminarily compressing the fuelmixture, a carbureter, a mixture supply conduit dividing into two branches. one branch opening into the inlet of the cylinder provided 'with a valve and the other valveless orifice completely smooth in the interior opening into the cylinder Wall at u considerable distance from the lower edge of the cylinder and being controlled hy the inner edge of the Workin piston, a slot in the piston Wall ofthe Working piston, ayalveless overflow channel on the Working cylinder and completely smooth in the interior and provided with an orifice opening into the crank case and an orice opening into the working chamber ofthe cylinder permitting the mixture compressed in the crank case to pass over through the piston Wall into the compression chamber of the cylinder when the first namedfori'lice registers With the slot in the piston Wall.

MARTIN BLAU. EMIL .FREYTAG 

